<template>
  <div>

    <!-- 评论列表 -->
    <div class="cmt-list" :class="showComment ? 'art-cmt-container-1' : 'art-cmt-container-2'">
      <van-list
      v-model="loading"
      :finished="finished"
      finished-text="没有更多评论了，请发表评论"
      @load="onLoad"
      :immediate-check="false"
      >
      <!-- 评论的 Item 项 -->
      <div class="cmt-item" v-for="item in commentList" :key="item.com_id">
        <!-- 头部区域 -->
        <div class="cmt-header">
          <!-- 头部左侧 -->
          <div class="cmt-header-left">
            <img :src="item.aut_photo" alt="" class="avatar">
            <span class="uname">{{item.aut_name}}</span>
          </div>
          <!-- 头部右侧 -->
          <div class="cmt-header-right">
            <van-icon  name="like" size="16" color="red"
            v-if="item.is_liking" @click="loveFn(item)"/>
            <van-icon name="like-o" size="16" color="gray"
            v-else @click="loveFn(item)"/>
          </div>
        </div>
        <!-- 主体区域 -->
        <div class="cmt-body">
            {{item.content}}
        </div>
        <!-- 尾部区域 -->
        <div class="cmt-footer">{{timeAgo(item.pubdate)}}</div>
      </div>
      </van-list>
    </div>

    <!-- 底部添加评论区域 - 1 -->
    <div class="add-cmt-box van-hairline--top" v-if="showComment">
        <van-icon name="arrow-left" size="0.48rem" @click="$router.back()" />
        <div class="ipt-cmt-div" @click="showComment = false">发表评论</div>
        <div class="icon-box">
            <!-- 评论 -->
            <van-badge :content="total_count===0?'':total_count" max="99" >
                <van-icon name="comment-o" size="0.53333334rem" @click="moveComment"/>
            </van-badge>
            <!-- 收藏 -->

            <van-icon name="star" size="0.53333334rem" color="red" v-if="addLike"  @click="changStar"/>
            <van-icon name="star-o" size="0.53333334rem" v-else @click="changStar"/>
            <!-- 分享 -->
            <van-icon name="share-o" size="0.53333334rem" />
        </div>
    </div>

    <!-- 底部添加评论区域 - 2 -->
    <div class="cmt-box van-hairline--top" v-else>
        <textarea v-fofo placeholder="友善评论、理性发言、阳光心灵"
         @blur="blurFn"
         v-model="comText"
         ></textarea>
        <van-button type="default" :disabled='comText.trim()?false:true' @click="sendComment">发布</van-button>
    </div>
  </div>
</template>

<script>
import { getCommentsAPI, commentsLikeAPI, cancelCommentAPI, commitCommentAPI } from '@/api'
import { timeAgo } from '@/utils/date'
export default {
  data () {
    return {
      // 偏移量,第一次传递不需要，所以初始化为null
      offset: null,
      // 评论列表
      commentList: [],
      // 评论切换
      showComment: true,
      // 评论总数
      total_count: 0,
      // 输入文本框的值
      comText: '',
      loading: false,
      finished: false,
      // 收藏
      addLike: false
    }
  },
  created () {
    this.getComments()
  },
  methods: {
    // 获取当前文章的评论
    async  getComments () {
      this.loading = true
      const { data: res } = await getCommentsAPI({
        id: this.$route.query.id,
        offset: this.offset
      })
      // console.log(res)

      // 合并
      this.commentList = [...this.commentList, ...res.data.results]
      this.total_count = res.data.total_count
      if (res.data.results.length === 0) {
        this.finished = true
      }
      // 将最后一条评论的id保存
      this.offset = res.data.last_id
      this.loading = false
    },

    // 时间格式化
    timeAgo,

    // 评论的点赞与取消
    async  loveFn (item) {
      item.is_liking = !item.is_liking
      console.log(item.is_liking)
      // is_liking 为true 调用点赞接口
      if (item.is_liking) {
        const res1 = await commentsLikeAPI(item.com_id)
        console.log(res1)
      } else {
        const res2 = await cancelCommentAPI(item.com_id)
        console.log(res2)
      }
      // is_liking 为false 调用取消点赞接口
    },
    // 评论失去焦点,这里必须拿到输入框的值后才能让它失去焦点，否则失去焦点后DOM销毁，拿不到输入框的值
    blurFn () {
      setTimeout(() => { this.showComment = true }, 0)
    },
    // 评论滑动
    async moveComment () {
      // 真实DOM都在document，所以即使不在一个vue组件中也是可以获取的
      // 获取点赞的那个DOM
      // scrollIntoView 进入视口
      document.querySelector('.bottom-box').scrollIntoView({
        behavior: 'smooth'
      })
    },
    // 发布评论
    async sendComment () {
      // 发布评论
      await commitCommentAPI({
        target: this.$route.query.id,
        content: this.comText.trim()
      })
      // 获取新的评论
      const { data: res1 } = await getCommentsAPI({
        id: this.$route.query.id,
        offset: null,
        limit: 1
      })
      // 添加到数组
      this.commentList.unshift(res1.data.results[0])
      this.total_count++
      this.comText = ''
      // 回到第一条评论，即我们刚刚发表的评论
      this.moveComment()
    },

    // 获取更多评论
    onLoad () {
      if (this.commentList.length > 0) {
        this.getComments()
      } else this.loading = false
    },

    // 收藏切换
    changStar () {
      this.addLike = !this.addLike
    }
  }
}
</script>

<style scoped lang="less">
.cmt-list {
  padding: 10px;
  .cmt-item {
    padding: 15px 0;
    + .cmt-item {
      border-top: 1px solid #f8f8f8;
    }
    .cmt-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      .cmt-header-left {
        display: flex;
        align-items: center;
        .avatar {
          width: 40px;
          height: 40px;
          background-color: #f8f8f8;
          border-radius: 50%;
          margin-right: 15px;
        }
        .uname {
          font-size: 12px;
        }
      }
    }
    .cmt-body {
      font-size: 14px;
      line-height: 28px;
      text-indent: 2em;
      margin-top: 6px;
      word-break: break-all;
    }
    .cmt-footer {
      font-size: 12px;
      color: gray;
      margin-top: 10px;
    }
  }
}
/*美化 - 文章详情 - 底部的评论页面 */
// 外层容器
.art-cmt-container-1 {
  padding-bottom: 46px;
}
.art-cmt-container-2 {
  padding-bottom: 80px;
}

// 发布评论的盒子 - 1
.add-cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  box-sizing: border-box;
  background-color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 46px;
  line-height: 46px;
  padding-left: 10px;
  .ipt-cmt-div {
    flex: 1;
    border: 1px solid #efefef;
    border-radius: 15px;
    height: 30px;
    font-size: 12px;
    line-height: 30px;
    padding-left: 15px;
    margin-left: 10px;
    background-color: #f8f8f8;
  }
  .icon-box {
    width: 40%;
    display: flex;
    justify-content: space-evenly;
    line-height: 0;
  }
}

.child {
  width: 20px;
  height: 20px;
  background: #f2f3f5;
}

// 发布评论的盒子 - 2
.cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 80px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  padding-left: 10px;
  box-sizing: border-box;
  background-color: white;
  textarea {
    flex: 1;
    height: 66%;
    border: 1px solid #efefef;
    background-color: #f8f8f8;
    resize: none;
    border-radius: 6px;
    padding: 5px;
  }
  .van-button {
    height: 100%;
    border: none;
  }
}
</style>
